FlyingCircus of Physics A roller-coaster car has a mass of 1240 kg when fully lo
ID: 1738749 • Letter: F
Question
A roller-coaster car has a mass of 1240 kg when fully loadedwith passengers. As the car passes over the top of a circular hillof radius 25 m, its speed is not changing. (a) Atthe top of the hill, what is the normal force (using the negativesign for the downward direction) FN on the carfrom the track if the car's speed is v = 8.1 m/s?(b) What is FN if v =18 m/s?
Chapter 6, Problem 46A roller-coaster car has a mass of 1240 kg when fully loadedwith passengers. As the car passes over the top of a circular hillof radius 25 m, its speed is not changing. (a) Atthe top of the hill, what is the normal force (using the negativesign for the downward direction) FN on the carfrom the track if the car's speed is v = 8.1 m/s?(b) What is FN if v =18 m/s?
Explanation / Answer
Use the concept of Newton's second law (F=ma). At the top of the hill, the forces acting on the car areFN and FG, and the acceleration is justcentripetal acceleration (V2/R). So basically: FN - FG =m(v2/R) Note that FG=mg FN - (9.8*1240) = 1240(8.12/25) Use algebra to find that FN = 15406N To do question b, apply the same method, except substitude in 18m/s for V.